Square D️ QO Circuit Breakers
A complete range of QO Combination AFCI, GFCI, and Dual-function circuit breakers.
Square D️ QO Circuit BreakersSquare D QO™ GFCI breakers now rated for high frequency: ground fault protection designed for the wide range of loads in electrified homes and light commercial applications.
"The HF-rated GFCI breaker was developed and validated through extensive lab and field testing, backed by over 100 years of Square D expertise." — Poonam Narang, Schneider Electric.
Key benefits of QO circuit breakers
Built to reduce unwanted tripping and fewer callbacks
Move to the next job faster.
Equipped for the loads in electrified homes and light commercial buildings
Supporting wide range of applications like HVAC, EV chargers, pool pumps, spas, ovens, and more.
Less wire clutter
Plug-on neutral (PoN) creates a more organized panel.
Efficient troubleshooting
LED indicators identify issues at a glance.
Streamlined installation
Ready-to-wire lugs help reduce labor time.
Ready for compliance
AFCI and GFCI options help meet NEC requirements where adopted.
Connections your way
Choice of plug-on neutral or pigtail connections.
Combination AFCI breaker (AFCI)
Detects parallel and series arcing in branch circuit wiring before ignition, meeting UL 1699 and NEC 210.12 requirements.
Product features
Product features
Combination AFCI | Dual function | HF-Rated GFCI | |
| Action | |||
Arc Fault (parallel + series) | Combination AFCI and GFCI | Ground Fault, now rated for high frequency | |
| Protection features | |||
| Pole configuration and amperage | 1P / 2P , 15-30 A | 1P / 2P , 15-20 A | 2P , 15-60 A |
| Plug-on neutral (PoN) compatible | |||
| Series arc fault detection | -- | ||
| Parallel arc fault detection | -- | ||
| Ground fault protection - personnel (5mA) | -- | ||
| Advanced features | |||
| High-frequency ground fault detection | -- | -- | |
| Self-diagnostic / end-of-life indication | |||
| Trip cause indication (diagnostic LED) | |||
Square D QO and Homeline plug-on neutral GFCI breakers, now rated for high frequency
Learn how the Square D QO and Homeline PoN GFCI breakers, now rated for high frequency, are designed for faster installs and reduced callbacks.
General and selection
How do I know if my panel uses QO breakers?
QO™ breakers include the Visi-Trip indicator; a small colored window on the face of the breaker that changes when the breaker has tripped. QO breakers are used in Square D™ QO load centers, which include a model number beginning with "QO" on the panel label. QO and Homeline™ are not interchangeable. Each breaker type fits only its corresponding load center with the exception of QOM-series main breakers, which both QO and Homeline load centers use.
What's the difference between QO and Homeline breakers?
QO and Homeline are both Square D residential circuit breakers, but they fit different load centers and cannot be substituted for each other. QO breakers have ¾-inch per pole size, while Homeline circuit breakers have 1-inch per pole size. QO breakers also feature a visible trip indicator (Visi-Trip) window and are generally considered the premium line for residential, light commercial, and three-phase work in QO load centers. Homeline circuit breakers are used in Homeline load centers and offer broad residential coverage at a value price point. Both families include Combination Arc Fault Interrupters (AFCI), Ground Fault Circuit Interrupters (GFCI) in both standard and high-frequency-rated options, and Dual Function (AF and GF).
What amperages are available in the QO breaker family?
QO 1-pole standard circuit breakers are available from 15-70 A, and 2-pole standard circuit breakers are available from 15-200 A. QO 1-pole Arc Fault or Dual Function circuit breakers are available in 15 and 20 A. QO 1-pole GFCI circuit breakers are available from 15-30 A, while 2-pole GFCI circuit breakers are available from 15-60 A.
HF-Rated GFCI
What is an HF-rated GFCI and when should I use one?
An HF-rated (high-frequency-rated) GFCI is a Class A GFCI certified under UL 943 HF to maintain personnel protection across leakage current at frequencies above 60 Hz. Square D QO GFCI circuit breakers, now rated for high frequency, are enhanced versions of the existing QO GFCI breakers rather than a separate product, designed to help expand ground fault protection across the wide range of loads in homes and commercial applications. They can be used anywhere a standard Class A GFCI is used and provide the same level of ground fault protection. They should be specified for circuits serving equipment with variable-frequency drives or power-conversion electronics, including but not limited to, heat pumps, mini-splits, EV chargers, pool pumps, and well pumps.
Will the QO plug-on neutral HF-rated GFCI breakers work in my existing QO load center?
It depends on the load center. Plug-on neutral GFCI breakers require a plug-on neutral load center. QO load centers manufactured after 2012 are plug-on neutral at 12 spaces / 100 A and above. Older load centers, and smaller 2, 4, 6, and 8-space units rated 100 A or less, use a pigtail neutral connection. Plug-on neutral breakers are not compatible with these load centers. Continue using the pigtail GFCI breaker listed for your load center. Verify that your load center is plug-on neutral before purchasing.
What is the NEC 2026 GFCI requirement for HVAC equipment?
The exception for listed HVAC equipment in NEC 210.8(F) expired September 1, 2026. In states and jurisdictions that have adopted NEC 2023 or 2026 without local amendment, outdoor outlets at dwelling units supplied by single-phase branch circuits rated 150 V or less to ground now require GFCI protection, including circuits serving heat pumps, AC condensers, and other outdoor HVAC units. The ampere threshold is 50 A or less under NEC 2023 and 60 A or less under NEC 2026.
Why does my GFCI circuit breaker keep tripping. What should I check?
Unwanted GFCI tripping has several possible causes beyond a true ground fault. Check for: moisture in outdoor or damp-location receptacles and conduits, LED lighting drawing inrush current on the same circuit, long cable runs with capacitive coupling, wiring errors such as shared or improperly bonded neutrals, or modern variable-speed equipment producing high-frequency leakage. The fix depends on the cause. Wiring errors and moisture need correction at the source, while high-frequency leakage from variable-speed equipment is typically resolved by installing an HF-rated GFCI breaker.